A thin-section technique for transmission electron microscopy of catalysts

Abstract

Transmission electron microscopy (TEM) is often used to image the different phases, the metal dispersion, and the pore structure of heterogeneous catalysts. Although fine particle dispersion ts the most common sample preparation method because of its simplicity, it suffers from a paucity of sample areas which are thin enough. A less common technique for catalysts is thin sectioning. Sprys et al reported that the thin section technique is prohibitively expensive due to damage to the diamond knife, although Sawruk et al reported satisfactory results using a diamond knife with a relatively large angle (55°). An improved thin section technique has been developed for catalysts which has proven to be practical and efficient. Three catalysts have been used to evaluate and compare these preparation techniques.The fine particle dispersion technique used in this evaluation involves spraying a suspension of the finely ground catalyst onto a holey Triafol film covered grid.3 Figure 1 is a SFM micrograph of an area of a TEM grid with a catalyst sample prepared by this technique. Most of the particles lying on the holey film are obviously too thick for TEM.